Azure event hub : System.Net.Sockets.SocketException: 'No such host is known'

Question

Getting error : System.Net.Sockets.SocketException: 'No such host is known' while connecting to Azure event hub from .Net console app to event hub

Answer 1

Hi @SAC_535

I follow that tutorial and worked just fine.
I've committed my code here : https://github.com/blucas2016/SampleEventHubMessageSend

You can clone and add your azure hub policy connection string.

(1) is the connection string from the hub policy, not the hub namespace (https://learn.microsoft.com/en-us/azure/event-hubs/event-hubs-get-connection-string)

(2) is the hub name

Once you run you should see this:

Receiver is the same this for (1)

For (2) you need to create storage container:
https://learn.microsoft.com/en-us/azure/event-hubs/event-hubs-dotnet-standard-getstarted-send#create-an-azure-storage-and-a-blob-container

Run the "SampleEventHubMessageSend" first so you have messages in the hub before running "SampleEventHubMessageReceive"

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Answer 2

Hi @SAC_535

You said you have define namespace, event hub and subscription. Did you create a access policy for you "hub entity"?
This is the name space. For the code we need to use the Event hub under "entities". Click on "event hubs" under entities and check it that has an access policy. Be careful to don't confuse with the "namespace" access policy. both "hub namespace" and "hub entity" have access "policy". For this code you need the "hub entity" policy connection string. You know you've got the correct one when the connection string finishes with ";EntityPath=[hub name]"

Did you set a access policy for you event hub entity?

If I delete my access policy I get the exact same error as you

check if you have the access policy set to manage. Ideally you should create 1 policy to send and another one to receive, but try a manage for now just to see it this is the issue.
Also check if the hub network settings is not blocking your machine, You can temporarily select "All Networks" just to test :

So, make sure you have a hub instance (not hub namespace) policy set to manage:

if you have to create one, get the connection string from that and add to the code
I also added code to force it to use websockets. try the above first. if it doesn't work, get a new version of my code